Check if the browser is closing in TabMetricsLogger

TabMetricsLogger generally shouldn't be invoked to log a UKM for a
background tab if the tab is closing, but there are lots of potential
edge cases where this could happen. If the browser window is being
closed, early exit instead of logging.

Bug: 784639
Change-Id: Ic7f39f1f0cbfbba1dd867195c91365afb630dc61
Reviewed-on: https://chromium-review.googlesource.com/905794Reviewed-by: François Doray <fdoray@chromium.org>
Commit-Queue: Michael Giuffrida <michaelpg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#535973}

chrome/browser/resource_coordinator/tab_metrics_logger_impl.cc

@@ -8,6 +8,7 @@
 #include <string>
 #include <vector>
 
+#include "base/stl_util.h"
 #include "base/time/time.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/custom_handlers/protocol_handler_registry.h"
@@ -17,6 +18,7 @@
 #include "chrome/browser/resource_coordinator/tab_manager.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
+#include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/custom_handlers/protocol_handler.h"
 #include "content/public/browser/render_frame_host.h"
@@ -175,15 +177,23 @@ void TabMetricsLoggerImpl::LogBackgroundTab(ukm::SourceId ukm_source_id,
     return;
 
   content::WebContents* web_contents = tab_metrics.web_contents;
-  Browser* browser = chrome::FindBrowserWithWebContents(web_contents);
-  if (!browser)
-    return;
 
   // UKM recording is disabled in OTR.
   if (web_contents->GetBrowserContext()->IsOffTheRecord())
     return;
 
+  // Verify that the browser is not closing.
+  const Browser* browser = chrome::FindBrowserWithWebContents(web_contents);
+  if (!browser ||
+      base::ContainsKey(
+          BrowserList::GetInstance()->currently_closing_browsers(), browser)) {
+    return;
+  }
+
   const TabStripModel* tab_strip_model = browser->tab_strip_model();
+  if (tab_strip_model->closing_all())
+    return;
+
   int index = tab_strip_model->GetIndexOfWebContents(web_contents);
   DCHECK_NE(index, TabStripModel::kNoTab);